Vented storage tank



March 15, 1950 'r. s. KINNEY VENTED STORAGE TANK Filed Nov. 4, 1957 Rm c m Em, 3 W 8 w E F m A 5 N H Hm I United States Patent 2 Claims. (Cl. 257-34) This invention relates to a vented storage tank and, more particularly, to a vented vessel for containing and heating viscous materials to temperatures above the volatization temperature of solvents contained in the viscous materials.

As a typical example, petroleum solvents are employed in asphaltic materials in varying amounts for a given weight of asphalt according to formulations developed and specified in road-building. Due to the tendency of the asphalt tobe or become too viscous under normal and cold weather conditions or to decrease viscosity for pump conveying and circulatory mixing, storage containers are usually provided with heater means. Such containers or tanks may vary in capacity between about 5,000 gallons and 20,000 gallons. During storage the asphaltic materials, therefore, are heated to maintain fluidity to temperatures above about 200 F. and up to 500 F. The presence in the materials of petro-solvents, volatile at temperatures of about 150 F., creates a problem. Storage vessels of the type used necessarily have vents open to the air. When the petrosolvents volatize a gas vapor forms and escapes from the vessel. This results in an imbalance in the asphalt-solvent ratio and the material rapidly falls-out of specification.

It is an important object of this invention to provide heated and vented storage means for heat responsive viscous materials including solvent in which heating and venting occurs simultaneously but solvent loss is minimized. This and other objects will be apparent from the following specification.

It will be understood that while I show a preferred form of my invention, other forms that fall fairly within the spirit and scope of the claimed invention are deemed part hereof. Modifications and changes likely to occur to persons skilled in the art are likewise considered as part of this invention.

Like reference characters are used to refer to like parts throughout, the drawings, in which:

Figure 1 is an elevational assembly view of a heated storage tank according to my invention;

Figure 2 is an enlarged cross-section view taken on line 2--2 of Figure 1; and

Figure 3 is a cross-section view taken on line 3-3 of Figure 2.

Referring to Figure 1, the vessel or tank 10 is supported on legs 12 in a typical horizontal position. Immersion heater tubes 14 extend along the lower part of the tank interior to circulate heat throughout its contents. A pump 16 draws fluid material to be stored through inlet 18 and delivers it to the tank. Pump 16 also is useful to withdraw the stored fluid and force it up and out counterbalanced delivery spout 20 and nozzle 22. An electrical control cabinet 24 contains electric supply and switching mechanism for motor 26 and heaters 14 when the latter are electrically activated.

An insulative jacket 28 normally encases tank 10 to preserve heat and prevent undue solidifying of the stored fluid. 1 i

The upper portion of tank'10 has an opening 30 provided with pipe flange ,32 which'receives and supports vent pipe 34 in an upright position. The upper end of plpe 34 is usually capped by a downwardly open coupling 36 or bent over end to exclude rain and the like while permitting air to move in and out.

Pipe 34 has fins 40 outstanding along its length and supported thereby. I have shown fins 40 as being spirally formed and attached to pipe 34 by flanges 42 in the conventional manner. Fins 40 are typical of many such heat radiating fins or spines well known in the art and I do not limit myself to the actual construction depicted.

In operation the contents of tank 10 are heatedby tubes 14 to a range of about 200500 F. The petrosolvents present usually have a temperature of rapid volatization above F. Under conditions of heat as mentioned the solvents tend to leave the asphaltic materials in gaseous phase and to rise in the vent tube 34. By rapidly absorbing and withdrawing heat from the vapor the wet airborne particles are caused to condense and collect within tube 34 without escaping from its upper end. As droplets form due to condensation they of course descend in the condenser tube and return to their source. A considerable saving of solvent is thus obtained while at the same time ratio changes in the asphaltic material are satisfactorily avoided. v

' Having thus described my invention, I claim:

1. A storage tank for viscous, heat responsive materials containing petrosolvents normally volatile above about 150 F. comprising: a closed vessel having inlet and outlet means for the contained materials, means within said vessel to elevate its contents to a heat range of about 200 to 500 F.; and a vapor vent rising from said vessel, said vent comprising an upright tube having heat radiating fins laterally outstanding therefrom, said fins and said tube being of such condensing capacity as to reduce solvent vapor temperatures within said vent tube to below their condensation point whereby they condense and return to the vessel and its contents.

2. The structure according to claim 1 in which the heat radiating fins consist of a helical metallic ribbon wrapped around said upright tube and intimately secured thereto.

References Cited in the file of this patent Patented Mar. 15, 1960 

